Shape-controlled solvothermal synthesis of Bi2S3 for photocatalytic reduction of CO2 to methyl formate in methanol

Abstract

Different shape of bismuth sulfide (Bi₂S₃), including nanoparticles, and urchin-like, microspheres hierarchical nanostructures, have been successfully fabricated using a facile and template-free solvothermal method. Their crystal and porous structures, morphologies, as well as the optical absorption were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis diffuse reflection spectroscopy (DRS) and nitrogen sorption. The electron microscopy observations showed that both the sulfur sources and solvents greatly affected the morphologies of the as-prepared Bi₂S₃. Compared with Bi₂S₃ nanoparticles, the hierarchical architectures exhibited higher activity for photocatalytic reduction of CO₂ to methyl formate (MF) in methanol, and Bi₂S₃ microspheres showed the highest activity. This was attributed to their special hierarchical structure, good permeability and high light-harvesting capacity.